How long does the 2oz jar of S5 cream last?

[breadrock]

Hey guys. I'm a poor student, but I'll have some extra finances due to being able to work more over the summer, so I want to stock up on new supplies. Cluelessly, I've been using Rogaine for about a year by itself, but now I realize I need to supplement with more and so S5 cream and Nizoral have my eye.

Just wondering, though, how long does the 2oz jar of S5 cream typically last? I want to get a few jars to last me, but I'm not sure how many I should get.

Thanks.